


Sustain Me

by beltainefaerie



Category: Sherlock (TV)
Genre: Alternate Universe - Vampire, Anal Fingering, Anal Sex, Blood, Blood Drinking, Brief mentions of Depression, First Time, Friends to Lovers, M/M, Vampire Sherlock, brief consideration of prostitution
Language: English
Status: Completed
Published: 2014-08-11
Updated: 2014-08-11
Packaged: 2018-02-12 18:26:37
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 3,034
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/2120196
Author URL: https://archiveofourown.org/users/beltainefaerie/pseuds/beltainefaerie
Summary: <blockquote class="userstuff">
              <p>John felt like Sherlock saved him that very first night. It takes him awhile to return that favor. But now their lives will never be the same.</p>
            </blockquote>





	Sustain Me

**Author's Note:**

  * For [tiger_in_the_flightdeck](https://archiveofourown.org/users/tiger_in_the_flightdeck/gifts).



> Thanks to demonicsymphony for getting me involved in pinch-hitting for this AU exchange. I had a lot of fun and made sure an amazing person got their gift.
> 
> Thanks also to the whole writer's circle for beta reading. You always make things so much better!

John’s elbow slipped, knocking his phone off the edge of the counter. Sherlock was walking by and reached out, gracefully catching it before it could hit the floor. He looked it over a moment and handed it back, leaning on the bar. 

“You don’t want this.” Sherlock purred, pushing the tumbler of whiskey away from the blond gentleman. 

“Ta, for the phone.” John said with a little salute, still not looking up. “Nice catch. But I think I know what I want to drink, thanks.” He grabbed the tumbler with a sigh and took a long pull.

“I wasn’t criticising your taste. I was suggesting that you are stronger than your brother and you don’t need to give in to drink. Even for someone recently invalided home, things aren’t so dire. Afghanistan or Iraq?”

John looked up at that, “Sorry?”

“Which one was it? Afghanistan or Iraq?"

“Afghanistan. Sorry, have we met?”

“No.”

“Then how did you…”

“He just does.” The barkeep interrupted. “Been in here off an’ on all week. Driving off the customers with his batty fortunetelling.”

Sherlock merely glared as the barkeep polished the glasses and walked to the other end to put them away.

Turning back to John the not quite stranger inquired, “How do you feel about the violin?.”

“I'm sorry, what?” John said, brow furrowed, clearly perplexed.

“I play the violin when I'm thinking and sometimes I don't talk for days on end. Would that bother you? Potential flatmates should know the worst about each other.”

“Potential… who said anything about flatmates?”

“I did, weren’t you listening? The bedsit doesn’t suit you.” _He wants company, but isn’t really ready to seek it out. May scare him off. Hopefully just mysterious enough to be interesting._ Sherlock caught himself.

_Why do I care?_

“Who _are_ you?” John said in amazement.

“Sherlock Holmes.”

John stood and offered his hand. Sherlock blinked for a moment, then took it. 

“John Watson.”

“Your therapist is right, by the way. The limp. Psychosomatic."

Sherlock shot him a grin that was nearly feral and John relaxed. It should have been predatory. Alarming. But it wasn’t. Not by a long shot.

Even when John was fairly certain he caught a glimpse of fang.

“Just you then, at the flat? I’ve mostly known vampires to be solitary, unless they’ve taken on a bloodslave. Which is fine by the way.” 

“I know it’s fine. But John, while I am flattered by your interest I must say that consider myself I am married to my work and I am not interested in any entanglements. For that matter, I also have a steady supply and I neither want nor need a bloodslave.”

John looked indignant, drawing himself up to his full height with a flash of anger in his eyes.”I am nobody’s slave, blood or otherwise. Just establishing. You’re alone. Like me.”

Sherlock smiled at the display. _John clearly had been thinking that might be the arrangement, exchanging for food and shelter, but proud enough to get angry when he seemed to be rebuffed. More and more interesting._

“No harm meant, I just wanted to be clear. I do, however, need an assistant, and your medical background would be invaluable.” Sherlock continued. “Irregular hours suit me and I doubt they’d bother you. With your shoulder, they gave you just enough _hemostrigis qurban_ to pull you through. Anticoagulant mostly, though the accelerated healing transfers a bit even when denatured. It didn’t affect you much, other than altering your natural sleeping patterns slightly.”

John’s eyes narrowed slightly, but he didn’t deny it.

”You don’t need as much as most people anymore, which is for the best since the nightmares prevent you from getting too much sleep as it is. The rest of your unit was lost and you have no idea how you managed to survive, let alone why. Most days you wish you hadn’t, which weighs on you. You know husbands, wives, mothers that would do anything to have brought their soldiers home. And you came back alone. Hence this bar and that tumbler. But I am telling you to stop. You don’t need it. Besides, I’ll wager I can find things far more diverting than oblivion in a bottle.”

He should have been offended, laid bare like that, but the fact was, it was damn impressive. Just about dead on, excepting the bit about his brother. But frankly there were people who had actually met Harry that made that mistake. 

“Brilliant.”

\---  
John shook his head. How he had ended up in that bar at that time, well, he never had put much stock in coincidences, but meeting Sherlock Holmes had to have been at best a one in a million chance. More distant probably. He figured he might at least look at the place. Nice street. Lovely building. He tried to remain objective when he was already thrumming with a constant refrain of _home_ before he even made it to the door.

Of course 221 was perfect. He’d never be able to afford it, but it was perfect. And then somehow, the miracle that was Sherlock Holmes had negotiated a price that was more than reasonable. Something about a favor done for the landlady.

And so it began.

\---

Six months later they were inseparable. It was hard to recall the time when he had been so desperate, so lonely. John shuddered to think what options he had been contemplating when they met. He wasn’t quite ready to give up, but closer than he’d have liked. In that tiny bar, he had honestly been wondering whether his body or his blood would be easier to sell. Somehow what was politely called “blood donor” or “professional victim” seemed more intimate than just sex. He hadn’t chosen yet, wasn’t even sure he needed to, not for sure. But if he hadn’t found a suitable position that week, he knew he would have to do something.

Then his life had been turned upside down. And being Sherlock’s assistant was more than ‘diverting’. It was finally living again. 

They were running down a narrow alley when Sherlock went down. John cried out his name, running to Sherlock’s side. Thankful for the pallet of cardboard boxes that had clearly broken his fall.

John could hear the scuffle as their quarry was taken down, but he hardly cared. Sherlock was all that mattered.

Kneeling beside him, John called Sherlock’s name again, grateful when he began to stir. Shifting instantly into doctor mode, John looked him over for injuries, finding nothing more serious than a scraped elbow and the usual smattering of nicks and stains from various experiments. Not healed yet. Some deductions were well within John’s purview. 

Sherlock pushed himself up to seated, blinking at John. “What happened? Did we catch him?”

John nodded. “Lestrade’s men nabbed him just as he went around the corner. They’re taking him in. He gave chase and you passed out when you tried to follow. When was the last time you fed?”

“Monday morning” Sherlock scoffed as though John was being ridiculous.

“Sherlock,” John said, blanching. “It’s Thursday! I don’t care what you think your body can do or how much you’ve been altered. You can’t run all over London like this with no food.”

“Thursday?” He appeared to calculate in his head a moment before nodding. “So it is.” Sherlock looked up helplessly. “I was following the case and I don’t typically carry blood bags with me.” With a resigned sigh, he tried to stand. “We can stop at Bart’s on the way home. I’m sure Molly can get something for me.”

“Not good enough.” John reached for Sherlock’s wrist anchoring him. “You are in no shape to go anywhere. Drink, now. Doctor’s orders.”

Sherlock's brow furrowed for a moment, his eyes widening in shock as John began unbuttoning his own collar with one hand, the other tightening on Sherlock’s arm. 

“Come on. I have what you need.”

His body was ignorable. Mere transport, until the needs became too difficult to disregard. Once John brought it back to his awareness, Sherlock’s hunger became an insistent hum. And with John on offer, it was utterly impossible to ignore. Sherlock swallowed hard and when he spoke, his voice was rough with need. “I haven’t done it like this in years, John. I don't know if I can stop when I need to.” 

John licked his lips and tilted his head to the side, fully baring his throat. His gaze was steady. “I trust you.”

Crawling forward, Sherlock straddled John’s legs and wrapped himself around the smaller man. He inhaled deeply, permitting himself to catalogue John’s scent in a way he had never allowed himself before. He moaned slightly, lips parting. His brain circled round and round, finding all the words that were John Watson, grounding him in the reality. He hadn’t fed like this since he had settled the question years ago of whether the blood lost significant potency in being bagged. It didn’t really; certainly nothing that made up for the time effort and sheer patience to find a proper (victim) source. 

_flatmate, partner, colleague, doctor, friend, protector, beloved_

_Beloved?_

Sherlock had no room for denial of the sentiment now it had surfaced. And if acknowledging how deeply he needed John Watson was what it took to keep him safe, he would. 

All the words that made him real trying to drown the instincts that drove him to consume, to feed, to take and take all of John Watson inside him. 

_Double entendre? Really?_ Sherlock scolded himself. He really was woozy, but he couldn’t help the deeper needs creeping in. Far beyond hunger now, though John was right. Unmistakably. He should never have been out this long without feeding, but if this was the result, he couldn’t say he was sorry.

He savored the feel of John against him, the perfect way they fit together. 

“You’re certain?” Sherlock asked. Once permitted, he had never asked again. Repetitious. Boring. But he had to know. This time, it had to be right… with John. 

“Sherlock, drink!” John said, his voice taking on the irrefutable edge of Captain Watson. A man who had commanded soldiers, saved lives. Sherlock bared his fangs, leaned in and drank. 

John let out a small strangled cry as the teeth penetrated his flesh, but he didn’t struggle. In fact, he reached up, his fingers tangling in Sherlock’s hair, pulling him close. 

John’s blood was thick, rich on Sherlock’s tongue, every bit as delectable as he knew it would be, though until this moment, he had firmly blocked himself from considering. Tang of salt from John’s skin, spike of adrenaline, mixing with the basic essence of John. Locked together, the damp ground, the filthy alley disappeared, leaving behind only this. Only John.

Sherlock needed to stop, shouldn’t take more, no matter how he wanted and managed to pull back. Lapping at the wounds, he felt them close. When Sherlock met John’s gaze, he took in their depth, pupil’s blown wide. His own were likely the same, but Sherlock considered possible reasoning. Had he taken too much, John slipping into shock? 

As if in answer, Sherlock found himself pulled down into a kiss that left no room for confusion, strong hands guiding him, John’s mouth crushing against his. 

_There’s always something._

Sherlock had never been so happy to be wrong.  
\---

John could hear the rush of blood in his veins like after a hard run. The spike of pleasure as Sherlock bite was unexpected, but strangely welcome. Life had given him more than his share of pain and none of it enjoyable, but this was different. He tangled his fingers in Sherlock’s hair, trying to focus, to make himself remember. Sherlock needed this. _Just helping, as his doctor, his friend._

_Fuck._

John stifled a moan. Sherlock pressed against him, needing him desperately, obeying his command. Something had shifted, some wall broken and John needed more. It was all he could do not to rub against him, this infuriating, perfect man straddling his lap. To drag his nails down his back, to rip at his clothes and take him right here. 

And the part of John’s mind that was aware this wasn’t his to take grew more distant as Sherlock drank. One hand slipped to Sherlock’s hip, anchoring him.

Too soon, it seemed, Sherlock pulled back. His hunger might have been slaked, but John felt his own was just beginning. 

John licked his lips, looking up at Sherlock and finding, almost startlingly, uncertainty furrowing his brow. It was a rare enough sight to give John pause, but he needed to feel those plush lips against him. Sherlock startled for a moment before settling more fully on John's lap, pressing himself down. John wanted little more than to grab Sherlock's hips, thrusting together until the pleasure overtook them, and it seemed like Sherlock might just let him, even here. Interesting to note. But for now John needed to get them out of this sodding alley away from Lestrade's team, who were still swarming about, likely to turn the corner at any moment. He had pushed as far as he dared and he didn't think the luck with their privacy was likely to hold. Much as he might relish the shock on the team's faces, he doubted this was the time. He pulled back with as much reluctance as Sherlock had moments ago.

Sure enough, a moment later Lestrade's himself came over to check on them. 

"We got him. What happened back here?"

"This git decided not to eat for days on end, as though he’s invincible."

Sherlock glared at them both, but stayed silent.

"No rejoinder? Scathing responses about our intellect, hygiene, idiotic human natures?" Lestrade's teased goodnaturedly. 

John interjected, "Clearly still unwell. Better get him home to bed." Sherlock's eyes widened slightly, but Lestrade didn’t seem to take any note as John continued, "I'm sure any statements could be taken over the phone or we could to yard in the morning if you really need us."

\---

They barely made it across the threshold of the flat.

“I did promise to take you to bed,” John said, tangling his fingers in Sherlock’s curls again. “Any objections?” 

Sherlock merely moaned softly and began divesting himself of clothes.

“Shall I take that as a no?” John said with a quirk of his brow, dragging Sherlock down into a kiss. 

“No objections at all,” Sherlock smiled and let himself be led to the bedroom.

 

“A bit late, with the blood exchange and all, but I am clean.”

Sherlock smiled. “I know. We can actually smell the difference. The ones that bite anyway are usually too high to care. And even high I was meticulous. And I want to feel you,” Sherlock said, eyes darkening as he opened the bedside table and retrieved a small bottle of lubricant.

John guided him back onto the bed, kissing and stroking his way down Sherlock’s chest and belly. He licked Sherlock’s hard shaft, hearing a hiss escape the vampire as John settled between his thighs. Sherlock arched up towards the touch of John’s tongue, but he pulled back, teasingly. “Sensitive, aren’t you?” 

Sherlock murmured his agreement. 

“Good. You’re beautiful this way. But I just can’t help thinking...” Flipping the top open with one hand, John set to work coating his own fingers. He placed one finger against Sherlock’s tightly furled hole, pressing in as he spoke. “You’ll be even more beautiful when I’m inside you. This is what you need, what no one expects you to want, isn’t it?“ 

“Yes, John, please!” Sherlock whimpered.

It was heady to see Sherlock so openly needy under him. How often had John had watched him ignore all needs? But now he was giving in, to this. To him. His breath quickened as he felt Sherlock contract around his fingers, then relax. Sherlock opening for him because he _wants_ this.

John’s life had changed so much to come to this moment. He had nearly lost everything, but would do it all again, if only for this. Them. He dropped light kisses anywhere he could reach as he pressed deeper, savoring this moment. 

“Oh, we’ll get there. When I know you’re ready.”

John resumed his attentions, appreciating every moan and whimper until Sherlock was taking three fingers easily and pressing himself down, his whole body begging for more. When John withdrew his hand, Sherlock cried out at the loss of contact. 

Chuckling darkly, John moved, slicking his hand over his cock quickly as he lined up. “I’ve got you,” John murmured, one hand smoothing down Sherlock’s side, coming to rest lightly on his hips.

They both groaned as he pressed forward, Sherlock thrusting back, coaxing him further until he was fully seated. John paused a moment, taking in Sherlock’s face, his lips parting in pleasure, his whole being relaxing in the bliss of being filled as he so desperately needed. But John needed too and he began to move, gripping tightening on Sherlock’s hips, his thrusts hard and insistent. 

Sherlock writhed under him, his moans becoming an incoherent tumble of John’s name and words for yes and more in every language he knew until he cried with pleasure. 

“Bite me again.” John urged Sherlock as he thrust deep. “Do it. Now!" 

Sherlock moaned beneath him and arched up, sinking his fangs into his earlier marks as John’s hips stuttered, his rhythm becoming irregular in his urgency. John sensed that Sherlock was not taking as deeply as before, but it did nothing to lessen the pleasure. The sensation was stunning. 

John felt Sherlock withdraw as he began to slide out and catch his breath.

“It’s never been like that.” Sherlock said, breathlessly, and looked into John’s eyes.

“No? Well, not a typical reaction to the bite, I’d wager.“

“You are hardly ordinary, John.”

“And you are magnificent.” John said, kissing him once more. “But, however extraordinary you may be, you do have to take care of yourself. This may have pushed us forward, but now I expect you to eat something. Every day. Bagged,” John mouth quirked in a devious smile, “Or otherwise.”

“Doctor’s orders?” Sherlock smiled back, eyes twinkling. “I think I can manage that.”

**Author's Note:**

> *The drug Sherlock mentioned, as hopefully can be gleaned from context, is denatured vampire blood used for medical purposes. It won't turn the recipient, but is prized for encouraging more rapid healing and can be use sparingly as an anticoagulant. Its name derives from hemoglobin, strigis (a Latin name for vampire/evil spirit) and qurban, a Semetic word for sacrifice. Someone at the drug company was not so pro-vampire and got in a dig or two. Usually abbreviated H.S. Qurban, or just Qurban for short, but goodness knows Sherlock would use the whole name.
> 
> Special thanks to Kat and Mandi for helping with the drug name.


End file.
